The present invention relates generally to a fixation device for fixing fractures. In particular, the present invention relates to an orthopaedic fixation device adapted to internally fix comminuted fractures in small bones with a complicated anatomy.
Difficult bony fractures are typically treated by open reduction and internal fixation. When a fractured bone is displaced and unstable, an orthopaedic implant is often used to internally stabilize or support the fractured bone. Different types of implants are produced by various companies for fixing fractures in different body parts. Generally, implants can reconstruct a stable bony framework by either load sharing or load shielding to allow the injured body part to be mobilized.
Fracture fixation can, however, become very complicated under a number of situations. When fractures occur in small bones, such as phalangeal bones, fracture fixation is difficult due to the small size of the bones as well as their close relations to multiple soft tissue structures. For small bone fixation, conventional implants can fix fracture fragments with only simple fracture configuration and reasonably large size. Normally, a bony fragment must be three times the size of an implant, such as a screw, in order for the bony fragment to be fixable by the implant. Currently, the smallest available screws for hand fractures have a diameter of 1.3 mm to 1.5 mm. Thus a fixable fragment must be larger than 4 mm. However, in a real life situation, fracture fragments can often be smaller than 4 mm. Consequently, no screws can be used to stabilize such small fragments to allow early mobilization of the injured body part.
Moreover, when comminuted fractures occur, bone collapses, complicated fracture lines, and multiple bone fragments can make fracture fixation much more difficult. Conventional implants can provide only a semi-rigid fracture fixation in cases of comminuted fractures. Due to such an insufficient support and/or fixation for the fractured bones, the mobility of the injured body part has to be sacrificed. Accordingly, conventional implants are inadequate to fix comminuted fractures to allow mobilization of the injured body part for its early rehabilitation.
Therefore, it is desirable to provide a fixation device to address the above problems. The present invention provides such a fixation device that is capable of fixing comminuted fractures, especially in a small bone.
The present invention provides a fixation device capable of fixing all types of fractures. In particular, the present invention provides a fixation device for internally fixing fractures occurred in small bones, such as phalangeal bones. The fixation device of the present invention comprises an elongated support plate, a transverse plate fixed to and extending transversely from the elongated support plate, and a fin member fixed to and extending transversely from the elongated support plate.
According to the present invention, the elongated support plate and the transverse plate define a plurality of first holes therein for receiving first fixing elements to mount the fixation device onto a bone. The first holes can be so located that the first fixing elements can prevent the fixation device from rotating and/or translating relatively to the bone after the fixation device is mounted onto the bone. Thus, the elongated support plate and the transverse plate can support the injured bone and allow early mobilization of the injured body part, such as neighboring joints of the fractured bone. In addition, the fin member is formed to be more flexible than the transverse plate. Thereby, the fin member can be bent to conform to the contour of the bone for fixing and/or stabilizing a fractured fragment or multiple fractured fragments. As a result, the fixation device can support an injured bone as well as fix or stabilize a fractured fragment or multiple fractured fragments. The fixation device of the present invention is a versatile implant, which can be fixed to any bone of any body part, from a phalangeal to toe bone. In one embodiment, the fixation device is formed to be fixed onto small bones, such as phalangeal bones.
According to an independent and separate aspect of the present invention, the fixation device can be formed so that it can fix or stabilize small fractured fragments. In an exemplary embodiment, the fin member can be formed to stabilize small fracture fragments, such as those under 4 mm. Additionally or alternatively, the fixation device of the present invention can fix different kinds of fractures, from simple to comminuted fractures, while allowing mobilization of the injured body part for its early rehabilitation. In a preferred embodiment, the fixation device can have a plurality of fin members adapted to fix or stabilize multiple fractured fragments, such as in the case of comminuted fractures.
Optionally, the fixation device can be formed to receive additional fixing elements to thereby support fractured fragments and to increase the strength of the fixation device. In one embodiment, the fin member can define a second hole therein for receiving a second fixing element for fixing fractured fragments. In an alternative embodiment, the fin member can have a remote end which defines a cut-out portion thereat for receiving a third fixing element to provide additional support for both the fractured bone and the fixation device.
The fixation device of the present invention can be otherwise formed to minimize the contact area between the fixation device and the bone and/or to decrease soft tissue impingement. In one embodiment, fin members can be removed from the fixation device when such fin members become unessential for fixation.
These and other features and advantages of the present invention will be readily apparent from the following detailed description of the invention, the scope of the invention being set out in the appended claims.